Australian wildfires threaten Sydney's water infrastructure

Firefighters battling the blazes for weeks received a reprieve of slightly cooler, damper conditions over Christmas, but the respite is not expected to last long.

Temperatures in New South Wales (NSW) state are forecast to head back toward 40 degrees Celsius early next week, fuelling fires near Warragamba Dam, which provides water to about 80% percent of Sydney’s 5 million residents.

“In recent days up to the cool change, the fires had been a potential threat to supply and assets, particularly in Warragamba and in the Blue Mountains,” a spokesman for the state’s water authority, WaterNSW, told Reuters.

“With the coming very hot conditions the fire situation may escalate in both those fronts and possibly elsewhere.”

Warragamba Dam is located 65km west of Sydney, catching water flowing from the mountains.

It is at 44.8% capacity, down from almost being full less than three years ago, as a prolonged drought ravage the continent’s east.

Despite the widespread destruction, the state’s water infrastructure network has not been damaged, the spokesman said.

There have been eight deaths, including two volunteer firefighters, linked to the blazes since they flared in spring.

With more than 40 dams across the state, WaterNSW supplies two-thirds of untreated water to the state’s water utilities, which then treat and clean the resource to provide drinking water to cities and regional towns.

Large quantities of ash and burned material could pose a threat to the quality of water in the dams if the fires are followed by heavy rain.

However, there is no significant rain forecast for NSW in the short-term and WaterNSW has put containment barriers to catch potential debris run-off, the water authority said.